Stable petroleum distillate fuels



STABLE PETROLEUM DISTILLATE FUELS Kurt F. Richards, Dyer, Ind., assignor to Standard Oil Company, Chicago, Ill., a corporation of Indiana No Drawing. Application November 30, 1953 Serial No. 395,271

14 Claims. (Cl. 44-66) This invention relates to stable petroleum oils and it is particularly concerned with the stabilization of hydrocarbon oils normally susceptible to oxidative deterioration at normal storage temperatures.

The deterioration of petroleum fractions, e.g. in the distillate oil range, manifests itself through the appearance of color, sediment, etc. in the oil. Sediment formation is particularly troublesome in oils used as fuels because it often results in clogging of equipment such as filters, screens, and nozzles. Petroleum fractions generally, however, with the possible exception of highly refined lubricating oils, are subject to oxidative deterioration in storage. And the prevention of such deterioration along with provision for finely dispersing and insoluble matter present in an oil are problems of extreme importance to the refiner. I

It is an object of the present invention to provide an additive for petroleum oils which will inhibit sedimentation, color formation, etc. and other undesirable deterioration. It is another object to disperse, and to thus render harmless, any sludge or color deterioration products occurring in such oils. Still another object is to provide a fuel oil resistant to sediment formation and sludging. v, i

It is a further object of the present invention to provide sludge-preventing additives for fuel oils comprising mixtures of virgin distillate and a cracked oil in the distillate fuel boiling range. These and additional objects will be apparent from the following detailed description of the present invention.

In accordance with the present invention, sediment formation may be prevented and oils of good color and overallstability may be assured by adding to petroleum oils a small amount of at least one polyamino compound of the hereinafter defined class along with a neutralized reaction product of a phosphorus sulfide and a hydronited States Patent carbon. More specifically, it has been found that a high degree of stabilization of petroleum fractions normally subject to oxidative deterioration upon storage at,normal temperatures may be obtained by adding thereto a small amount of a neutralized reaction product of a phosphorus sulfide and a hydrocarbon, e.g. that of P 5 and a butylene polymer, and at least one N-alkyl-propylene diamine compound (containing from about 6 to about v30 carbon atoms as the N-alk'yl radical) selected from-the group consisting of N-alkyl alkylene polyamiries containing one primary amino nitrogen atom and carboxylic acid salts thereof. These constituents are added in amounts sufficient to inhibit deterioration, e.g. generally from about 0.001% to about 0.1% and preferably from about 0.005 to "about 0.05 Thus, for example, distillate fuel oils containing about 0.005% of an additive comprising 0.004% of .an.N-alkyl propylene diamine, 0.001% of an outstanding ability to stabilize such oils from deterioration resulting in discoloration, sediment, etc., but in addition to be able to disperse any sediment which might form or which might have been present in the oil prior to introducing the additive and to impart substantial corrosion inhibiting properties to the oil.

More specifically, there may be employed such amines as N-n-cetyl-propylene diamine, the various Duomeens (products of Armour Chemical Division) which have the general formula RNHCH CH CH NH wherein R may be derived from coconut fatty acid (Duomeen C), from tallow fatty acid (Duomeen T), from lauric acid (Duomeen 12), or from soya fatty acid (Duomeen S), etc. The Duomeens are industrial'or technical grade chemicals with an amine content of approximately calculated as diamine. The approximate melting ranges for each of the aforementioned Duomeens are: Duomeen C-20 to 24 C., Duomeen 1228 to 32 C., Duomeen S38 to 42 C., and Duomeen T -44 to 48 C.

Phosphorus sulfide-hydrocarbon reaction products of the type which may be employed in accordance herewith may be readily obtained by reacting a phosphorus sulfide with a hydrocarbon at a temperature of from about 200 F. to about 600 F., and preferably from about 250 F. tofiabout 500 F., using from about 1% to about 50%,

and preferably from about 5% to about 25%, by Weight, .of the phosphorus sulfide in the reaction.

carbon reaction products contain both sulfur and phosphorus. The reaction may if desired be carried out in the presence of an additional sulfurizing agent or the phosphorus sulfide-hydrocarbon reaction product can be sulfurized, as described in US. 2,316,087 issued April 6, 1943, to James W. Gaynor and Clarence M. Loane.

The hydrocarbon constituent of this reaction is preferably a mono-olefin hydrocarbon polymer resulting from the polymerization of low molecular weight mono-olefinic hydrocarbons or isomono-olefinic hydrocarbons, such as propylene, butylenes, and amylenes or the copolymers ,obtained by the polymerization of hydrocarbon mixtures containing isomono-olefins and mono-olefins or mixtures of olefius in the presence of a catalyst, such as sulfuric acid, phosphoric acid, boron fluoride, aluminum chloride or other similar halide catalysts of the Friedel-Crafts type.

The polymers employed are preferably mono-olefin polymers or mixtures of mono-olefin polymers and isomono-olefin polymers having molecular weights ranging from about 150 to about 50,000 or more, and preferably from about 300 to about 10,000. Such polymers can be obtained, for example, by the polymerization in the liquid phase of a hydrocarbon mixture containing mono-olefins and isomono-olefins such as butylene and isobutylene at a temperature of from about 80 F. to about F. in the presence of a metal halide catalyst of the Friedel- Crafts types such as, for example, boron fluoride, aluminum chloride, and the like. In the preparation of these polymers there may be employed, for example, a hydrocarbon mixture containing isobutylene, butylenes and butanes recovered from petroleum gases, especially those gases produced in the cracking of petroleum oils in.

themanufacture of gasoline. U.S. 2,407,873 to Evening et al. describes a particularly suitable technique for polymerizing such olefins in the presence of an aluminumchloride-hydrocarbon complex catalyst.

Essentially paraffinic hydrocarbons such as bright stock residuums, lubricating oil distillates, petrolatums or paraffin waxes may be used. The condensation-products of any of the foregoing hydrocarbons or their halogen derivatives, with aromatic hydrocarbons can also be employed.

Examples of high molecular weight olefinic hydrocarbons which can be employed as reactants are cetene (C cerotene (C melene (C and mixed high molecular weight alkenes obtained by cracking petroleum oils. Other olefins suitable for the preparation of the herein described phosphorus sulfide reaction products are olefins having at least 20 carbon atoms in the molecule of which from about 12 carbon atoms to about 18 carbon atoms, and preferably atleast 15 carbon atoms, are in a long chain. Such olefins can be obtained by the dehydrogenation of parafiins, such as by the cracking of paraffin waxes, or by the dehalogenation of alkyl halides, preferably long chain alkyl halides, particularly halogenated parafiin waxes. Also, olefins derived from the synthol or hydrocarbon syntheses process may be employed. These are essentially straight chain compounds varying widely in molecular weight.

Also contemplated within the scope of the present invention are the reaction products of a phosphorus sulfide with aromatic hydrocarbons such as benzene, naphthalene, anthracene, toluene, diphenyl, etc. and alkylated aromatic hydrocarbon such as, for example, an alkyl benzene characterized by having at least one alkyl group of at least four carbon atoms, and preferably at least eight carbon atoms such as a long chain paraffin wax.

The phosphorus sulfide reactant can be any phosphorus sulfide, such as for example, P 53 P 8 P 8 and preferably P 8 The phosphorus sulfide-hydrocarbon reaction product normally shows a titratable acidity which is neutralized by treatment with a basic reagent. The phosphorus-sultide-hydrocarbon reaction product when neutralized with a basic reagent containing a metal constituent is characterized by the presence or retention of the metal constituent of the basic reagent. Other metal constituents such as a heavy metal constituent can be introduced into the neutralized product by reacting the same with a salt of the desired heavy metal.

The term neutralized phosphorus sulfide-hydrocarbon reaction product as used herein means a phosphorus sulfide hydrocarbon reaction product having at least about 1% of its titratable acidity neutralized by the reaction with a basic reagent and includes the neutralized phosphorus sulfide-hydrocarbon reaction products containing a metal constituent resulting from said neutralization or resulting from the double decomposition of the phosphorus sulfide-hydrocarbon reaction product treated with a heavy metal salt.

The neutralized phosphorus sulfide-hydrocarbon reaction product can be obtained by treating the reaction product with a suitable basic compound such as a hydroxide, carbonate, sulfide, or an oxide of an alkaline earth metal, e.g. calcium or barium, and preferably the latter, or an alkali metal such as, for example, potassium hydroxide or sodium hydroxide. Other basic reagents can be used such as, for example, ammonia or an alkyl or aryl substitute of ammonia such as amines. The products are neutralized by mixing a suitable base (e.g. a 50% solution of KOH) therewith and heating to a temperature in the range of from about 200 to about 400 F. After the base and phosphorus sulfide hydrocarbon reaction product are mixed and neutralized, they are preferably steamed at a temperature of about 400 F. to about a half hour. The steaming may take place during neutralization.

For a more complete description of neutralized products of this type and method of obtaining same, reference is made to US. 2,316,080, 2,316,082 and 2,377,955.

The salts of the polyamines which may be employed in accordance herewith may be prepared by reacting, under carefully controlled, non-dehydrating conditions, i.e. below about 200 F. and preferably below about 195 -F., a carboxylic acid .containing from about 6 to about 20 carbon atoms, and preferably at least about 12 carbon atoms, e.g. hexanoic, nonanoic, lauric, stearic, oleicflinoleic, linolenic, palmitic, etc, with any .of the hereinabove described amines to obtain either the monoor di-substituted acid salts of the amines. Care must be taken in the preparation of such salts inasmuch as prolonged exposure to temperatures higher-than about 200 F. results in the formation of amides or even glyoxalidines (if 1,2-substituted polyamines are employed) upon splitting out water. Among thevery economical, commercially available salts of this type are the oleic acid monoand/or di-salts of the Duomens (above described), particularly of Duomeen T.

Whereas the additive of the present invention is generally useful in petroleum distillates, and particularly cracked distillate fuels, it is especially useful in stocks of the type generally referred to as light catalytic cycle oil and fuel containing such'an .oil. Such a catalytic cycle oil is obtained from .a catalytic hydrocarbon cracking operation in which a' gas oil or heavier hydrocarbons such as reduced crude is cracked at a temperature of about 800 F. to about 1050 F. at a pressure of about atmospheric to about 50 pounds per square inch in the presence of suitable catalysts, such as for example silica-magnesia, silica-alumina, and other well-known cracking catalysts. A method of conducting a fluidized catalytic cracking operation is described in US. 2,341,193 issued to Fred W. Scheineman, February 8, 1944. The product fraction referred to herein is the heavier-than-gasoline fraction ordinarily called light gas oil or catalytic light cycle stock. A catalytic light cycle stockof the type particularly suitable for blending with virgin heavy distillates is a fraction having an aromatic content of at least about 40 to about 50% and a distillation range between about 425 F. and about 560 F. A typical analysis of a suitable light catalytic cycle stock shows the material to be composed substantially of about 10% normal C parafiins, about of other parafiins and naphthenes, about 5% mononuclear aromatics which are mainly monoto hexaalkylated benzenes, and about 40% polynuclear aromatics which are mainly alkyl naphthalenes, largely methylated naphthalenes. The boiling range of a typical light catalytic'cycle stock by A.S.T.M. distillation may be approximately:

- F. Initial boiling point 430 10% over i 448 over 478 over 518 Maximum boiling point 552 cracked (thermally or catalytically) or virgin or mixtures of these. Thus, petroleum distillates generally such as internal combustion engine fuels, furnace oils, burner oils, heater oils, kerosene, heavy industrial residual fuels (e.g. Bunker C), jet fuels, blending oils, stripper stocks, etc.,

which the additives of the present invention are added may have been refined by any of the many well-known techniques, e.g. caustic washing, acid treatment, Doctor flan oleic acid salt of Duomeen T demonstrated the eifec= tiveness of such combination to be about the equal of the polyamine plus the neutralized phosphorus and sulfur containing compound. Whereas, a two-component addisweetening, clay treating, etc., prior to additive introduc- 5 tive, i.e. polyamine or polyamine oleate plus neutralized tron. P 5 butylene polymer, gives excellent protection, the The oils which may be stabilized by the additives of combination of polyamine, polyamine salt and neutralized the present invention may be cracked, virgin or mixtures phosphorus sulfide-hydrocarbon reaction product gives a of these. Even blends of two different virgin oils, which substantially improved result.

Table 1 r KOFLNeutralized PISB- Neutrallzed Prsr-butyl- No Additive bntylene polymer (ca. ene (ca. 1,000 mol. wt.) 1.000 mol. wt.) prodproduct plus A -l-B not 1 plus A Rust protection: 4

(1) Water layer- 24 hours Severe rust No rust No rust. 144 hours do do Do. 300 hou ..do Rust on edges... Do. (2) Oil layer 24 hours do No rust D0, 144 hour do do Do. 300 hours (in do Do, Fllterability 5 after- 50 ml. 110 seconds 26 seconds 22 seconds. 200 ml 335 seconds 30 secon s 24 seconds. 400 ml. 34 seconds 26 seconds. Crucible mat Many brown-gray specks Brown tint and specks" Few small gray specks. Appearance after aging 1 Cloudy Slightly cloudy Bright. a Color after aging 1 a Light- Light. Sediment after aging 1 Very. mnon Trace. None.

. Em loyed in amount of 0.005%.

I A: uomeen T (Armour Chemical Division)employed in an amount oi 0.005%.

3 B=Duorneen T Oleate (Armour Chemical Dlvlslon)employed in amount of 0.001%.

4 50 milliliter samples of furnace oil were filtered into bottles and doped with additive. Bright steel strips were immersed in the oil for 5 minutes, then withdrawn. Twenty-five milliliters of water were added to the bottles, and the bottles were thoroughly shaken. The steel strips were then relmrnersed and left to stand in the open bottles for 144 hours. The strips were then withdrawn. dipped in mineral oil, allowed to drain, and hung in room air. The strips were examined after 24 after 144, and after 300 hours.

6 500 milliliter samples of furnace oil, with and with hours at about 220 F. The samples were allowed to cool, and then filtered through 1 square centimetcroi filter paper having a pore size of 10 microns, using a constant head of 12 inches of oil. collect successive 50 ml. increments of oil was recorded. The time required for the first, fourth and eighth 50 ml. portions lsgiven above. The high sediment and gum content oil becomes progressively harder to filter whereas the time for those containing the additive changes very little from start to finish.

i 500 milliliter sam les of furnace oil, with and without additive, were shaken with 500 m1. of tap water in a separatory funnel. The oil and water layers were allowed to separate for minutes; the free water was then drawn on, and the interfacial rag and the oil layer were filtered through a medium porosity irltted-glass crucible. The color and nature of the mat retained in the crucible indicate the tendency of the oil to sludge after contact out additive, were aged in open bottles in an oven for 20 V The time necessary to' with water. The lighter the mat the less the slndglng tendency. I

1 At the completion of the filtration, data for which are set forth above under Filterability, the filtered samples were returned to bottles and stoppered and then allowed to stand at room temperature [or seven days. The results given are a result of visual examination.

5 Run with different sample of control oil but under essentially identical conditions.

because of solubility differences result in the formation of sediment when admixed, may be stabilized thereby.

The herein described additives are outstanding in many ways. Thus, the additive imparts rust protection to metal surfaces in contact with the oil, inhibits sediment formation, improves filterability by dispersing any sediment formed, inhibits color degradation, decreases wear of internal combustion engine parts (as demonstrated by the data in Table 3), etc. In Table 1, therefore, laboratory data are set forth which serve to demonstrate many of these improvements. The footnotes (1 through 4) to 'Table 1 explain the tests employed and their significance. Field tests have borne out the expected superiority of the additive in commercial use. Many gallons of potentially sediment-containing fuel oil have been successfully 1nhibited against this and other results of deterioration by at the same time in systems employing uninhibited oil were heavily coated and subject to clogging at any moment.

Additional tests of the type set forth in Table l on 'the same type fuel oil inhibited with a small amount of a neutralized P S -butylene polymer reaction product and phorus-sulfide hydrocarbon reaction products. These oil.

, various purposes.

data are of a-qualitative nature and clearly demonstrate on a laboratory scale the ability of the additives of the present invention to inhibit color degradation, sediment formation, etc. in a furnace oil comprising 60% virgin distillate and 40% fresh, caustic washed catalytic cycle Datajare included which compare the effectiveness of the herein disclosed polyamines with other amines which have heretofore been added to petroleum oils for The data in Table 2 with the exception of the appearance of the crucible mat are based 'on the appearance of a furnace oil having the same composition as that employed in the tests recorded in Table 1, containing the additives indicated, after being heated for '20 hours at 200 F. and then held at room temperature for an additional 48 hours. The crucible data are obtained on the same oils in accordance with the test described in footnote 3 of Table 1, prior'to heating the oils for 20 hoursat 200T F. p v

a rat Table2 PzSs-Butylene Polymer (ea. Duo

Example Amine 1,000 mol. wt.) meen Appearance of Reaction Prod. T Crucible After Color Brightness Sediment Ole- Test 1 ate Amount Amount 1 (control) Deep purple flecks- Dark.-- V. cloudy Much 2 Duomeen T .004 A 2 .005 .001 Light pink cast Light" Clear None.

.005 B 3 .005 Gray cast do.... do.... Do. Duomeen C... .004 A 005 .001 o... 110.... S1. cloudy.. Do. Duomeen T .004 B 005 .001 do do..- V. clean..- Do. Duomeen S. .004 A .005 .001 Gray brown cast -do Clear Do. Duomeen l2 .004 A .005 .001 Deep gray cast do do o. N-n-dodeeylethylenerarnine- .004 A .005 001 Pink cast do Cloudy Moderate N-n-lauryldiethylene-diamine. .004 A .005 001 do do.. S1. cloudy-- Trace. Duomeen '1 .004 A .005 do .-do V. clean... None Phenylene diarnine .005 A .005 Chocolate mo Dark.-. Cloudy..- Much N-hydroxy dodecyldiethylene-triamine .004 A .005 001 Tan gray cast Light-. S1. cloudy" Trace 1 See footnote 6 to Table 1 (supra) for explanation of test resulting in these observations. 3: i A=KOH neutralized and steamed (at 400 F.) reaction product of P285 and butylene polymer. B =BB.(OH): neutralized and steamed (at 400 F.) reaction product of P285 and butylene polymer.

The surprising ability of additives of the present invention in preventing wear of internal combustion engine parts is demonstrated in Table 3. A diesel fuel comprising 60% straight run and 40% catalytic cycle oil having .01% concentration of an additive comprising 40% Duomeen T, 10% Duorneen T-mono-oleate and 50% of a potassium hydroxide neutralized reaction prod-- not of P and a butylene polymer having a molecular weight of about 1000, was compared with the same oil without the additive in a General Motors ll7 Diesel engine. This engine is a typical one-cylinder model of the General Motors 7:1 series engines.

Table 3 Control (D ndoped Diesel Fuel) Diesel Fuel Plus Additive Top compression ring:

(a) Weight loss grams) (b) Gap increase (inches) Total compression rings:

. (a) Weight loss (grams) 1. (b) Gap increase (inches) Other tests in which a diesel fuel comprising 100% of a low sulfur catalytic cycle oil was employed in the same engine, the-improvement resulting from the presence of 0.1% of the additive was about 80% reduction of top ring wear and about 90% of total compression ring Wear. Additional tests in a Caterpillar one cylinder test diesel engine demonstrated much the same improvement in wear characteristics.

As indicated above, the additives of the present invention are useful in straight run stocks (virgin) and blends of different virgin stocks. Thus, as shown in T able,4, the improved color inhibition in such oils when employing an additive of the present invention is substantial.

1 Blend of CuClz sweetened Mid-Continent virgin heater oil distillate and sulfuric acid treated West Texas virgin heater oil distillate.

l 50% KOH neutrali" ed reaction product of P285 and butylene polymer of about 1000 molecular weight. 40% of Duomeen '1 and of Duomeen T ntono-cleate.

8 Sulfuric acid treated West Texesheateroildistillate.

4 Heated for one hour at 290 Rand observed.

The introduction of the additive of the present invention to distillate fuels and the like is greatly facilitated by the use of concentrated oil solutions of such additives. It has, for example, been found especially desirable to use a 10% concentrate of such additive in an oil such as light catalytic cycle oil. A typical concentrate comprises 90% solvent and 10% of an additive consisting of 50% neutralized phosphorus sulfide-hydrocarbon reaction product, 40% alkylene polyamine and 10% carboxylic acid salt of such amine. Such concenirate is used for blending with the oil in whatever proportions may be desired and particularly to obtain a finished product containing the specified percentages of individual constituents. Whereas a 10% concentrate is specifically referred t0, it should be understood that such concentration may vary Widely and that those as high as 50% or more may be found useful under certain circumstances and are within the scope of the present invention. Moreover, although the light catalytic cycle oil is especially Well adapted for use as the carrier or solvent in such a concentrate, any other suitable hydrocarbon oil may be employed.

Percentages given herein and in the appended claims are by weight unless otherwise specified.

Because of the dispersion of water into the oil eliected by the additives of the present invention, it is sometimes desirable to employ a surface active agent in addition thereto to prevent hazy oils. Thus, various oil-soluble anionic and cationic surfactants such as the di-alkyl sodium sulfosuccinates, sodium cetyl sulfate, petroleum sulfonates, cetyl pyridinium chloride, octadecylarnine acetate, etc. may be employed. Such surfactants will vary in effectiveness with the particular oil, the amount of water, the physical state of the water in the oil, i.e. whether it is suspended, dissolved, etc., the range of temperature over which the oil may be stored, etc., but in general are effective in amounts between about 0.001

to about 0.05% by volume based on total oil. Greater and lesser amounts may be found useful under certain circumstances. Thus, haze .was successfully inhibited in a fuel oil composition comprising an oil consisting of 60% virgin furnace oil distillate and 40% catalytic cycle oil which had been stabilized against color and sediment formation with 0.01% of an additive comprising 0.005% of neutralized P 8 butylene polymer reaction product, 0.004% of Duorncen T and 0.001% ct Duomeen T--monooleate, by the addition of 0.002% by volume of sodium mahogany soap derived from the fuming sulfuric acid treatment of a hydrocarbon oil in the preparation of a Technical White Oil. In place of the sodium mahogany soap of the above example, other surfactants of the type above enumerated may likewise be employed.

Having thus described the present invention, what l claim as novel and desire to protect by Letters Patent is set forth in the following claims.

I claim:

1. A distillate petroleum fuel heavier than gasoline containing from about 0.001% to about 0.1% of a reaction product of a phosphorus sulfide and a non-gaseous higher hydrocarbon which has been neutralized with a basic reagent and from about 0.001% to about 0.1% of an N-alkyl propylene diamine which has the general formula RNHCH CH CH' NH and which contains from about 6 to about 30 carbon atoms in the N-alkyl radical.

2. The composition of claim 1 wherein the N-alkyl group is derived from the alkyl radical of tallow fatty acids.

3. The composition of claim 1 wherein the neutralized reaction product is a reaction product of P S and an olefin polymer.

4. The composition of claim 1 wherein the neutralized reaction product is a reaction product of P 8 and an olefin polymer which has been neutralized with an alkali metal hydroxide.

5. The composition of claim 1 wherein the distillate petroleum fuel is a blend of virgin stocks.

6. A distillate petroleum fuel heavier than gasoline containing from about 0.001% to about 0.1% of a reaction product of a phosphorus sulfide and a non-gaseous higher hydrocarbon which has been neutralized with a'basic reagent, from about 0.001% to about 0.1% of an N-allcyl propylene diamine which has the general formula RNHCH CH CH NH and which contains from about 6 to about 30 carbon atoms in the N-alkyl radical and fromv about 0.001% to about 0.1% of a higher aliphatic carboxylic acid salt of such an N-alkyl propylene diamine.

7. The composition of claim 6 in which the carboxylic acid is oleic acid.

8. The composition of claim 6 in which the N-alkyl radical is derived from the alkyl radical of tallow fatty acids.

9. The composition of claim 6 in which the reaction product is a reaction product of P 8 and an olefin polymer.

10. The composition of claim 9 in which the reaction product has been neutralized with a basic barium compound.

11. The composition of claim 9 in which the reaction product has been neutralized with an alkali metal hydroxide.

12. The composition of claim 11 in which the alkali metal hydroxide is potassium hydroxide.

13. A distillate petroleum fuel heavier than gasoline containing from about 0.001% to about 0.1% of a potassium hydroxide neutralized reaction product of P 8 and a butylene polymer, from about 0.001% to about 0.1%-of an N-alkyl propylene diamine which has the general formula RNHCH CH CH NH wherein the N- alkyl radical is derived from the alkyl radical of tallow fatty acids and from about 0.001% to about 0.1% of an oleic acid salt of said N-alkyl propylene diamine.

14. A concentrated solution in a distillate petroleum fraction heavier than gasoline of from about 10 to about 50% of a distillate fuel oil additive comprising about 50% of a reaction product of a phosphorous sulfide and a non-gaseous higher hydrocarbon which has been neutralized with a basic reagent, about 40% of an N-alkyl propylene diamine which has the general formula RNHCH CH CH NH and which contains from about 6 to about 30 carbon atoms in the N-alkyl radical and about 10% of a higher aliphatic carboxylic acid salt of such an N-alkyl propylene diamine.

References Cited in the file of this patent UNITED STATES PATENTS 2,305,674 Chenicek Dec. 22, 1942 2,316,080 Loane et al. Apr. 6, 1943 2,316,087 Gaynor et al. Apr. 6, 1943 2,329,251 Chenicek Sept. 14, 1943 2,369,490 Proell Feb. 13, 1945 2,507,731 Mixon May 16, 1950 2,534,217 Bartleson Dec. 19, 1950 2,684,292 Caron et al. July 20, 1954 2,712,528 Hill et al. July 5, 1955 2,736,658 Pfohl et al. Feb. 23, 1956 2,771,348 Meguerian Nov. 20, 1956 

6. A DISTILLATE PETROLEUM FUEL HEAVIER THAN GASOLINE CONTAINING FROM ABOUT 0.001% TO ABOUT 0.1% OF A REACTION PRODUCT OF A PHOSPHORUS SULFIDE AND A NON-GASEOUS HIGHER HYDROCARBON WHICH HAS BEEN NEUTRALIZED WITH A BASIS REAGENT, FROM ABOUT 0.001% TO ABOUT 0.1% OF AN N-ALKYL PROPLENE DIAMINE WHICH HAS THE GENERAL FORMULA R NHCH2CH2CH2NH2 AND WHICH CONTAINS FROM ABOUT 6 TO ABOUT 30 CARBON ATOMS IN THE N-ALKYL RADICAL AND FROM ABOUT 0.001% TO ABOUT 0.1% OF A HIGHER ALIPHATIC CARBOXYLIC ACID SALT OF SUCH AN N-ALKYL PROPLENE DIAMINE. 